1. Field of the Invention
The present invention relates to a radio communication terminal operable with electric power supplied from its built-in battery, and particularly to a cellular video telephone.
2. Related Art
JP-A-8-9347 discloses a cellular video telephone having a built-in or internal battery therein. This device has a power monitoring circuit, which detects remaining electric power of the built-in battery, and prolongs communication period by varying data transmission speed in response to the detected remaining battery power. Specifically, a frame rate, which is the number of picture images to be coded and transmitted per second, is calculated based on the detected remaining battery power, and dynamic or real-time image signals are coded by an image coding circuit at the calculated frame rate. Thus, the power consumption in the image coding circuit is reduced as the remaining battery power decreases, while reducing motions of dynamic images which results in lessening of the quality of dynamic image display to some extent. However, the reduction in the power consumption of the image coding circuit is still small in comparison with the total power consumption of the cellular video telephone.